The invention relates generally to the packaging of small deployable reflector antennas, and in particular to reflector antennas that can be packaged within CubeSat dimensions.
The process of launching satellites from earth's surface into space subjects them to gravity and additional acceleration and aerodynamic loads from the launch vehicle. These loads create large stresses in any spacecraft components not uniformly supported by the launch vehicle and bus structures. To allow large components to be adequately supported and aerodynamically shielded by the launch fairing, they are often collapsed to a smaller configuration. Once in space, the components are deployed into their larger operational configurations. Reflector antennas, an application of the current invention, are often many times larger than the launch vehicle fairing and must be compactly packaged for launch and unfurled once in orbit. Such reflectors are used for space communications, radar and other radio frequency missions.
Greschik proposed a deployment concept for a parabolic reflector in which incisions were made in a flexible shell surface of a parabola to transform the doubly curved surface into a quasi-foldable mechanism (G. Greschik, “The Unfolding Deployment of a Shell Parabolic Reflector,” 1995, AIAA-95-1278-CP). However, this achieved poor packaging in either the radial or height directions. Tibbalds devised a new way of optimizing the folding scheme to improve on packaging (B. Tibbalds, S. D. Guest and S. Pellegrino, “Folding Concept for Flexible Surface Reflectors.” 1998 and B. Tibbalds, S. D. Guest an S. Pellegrino, “Inextensional Packaging of Thin Shell Slit Reflectors” Technische Mechanik, 2004). A solid surface reflector is cut into spiral gores that fit together in a cylindrical manner about a central hub when packaged resembling a flower. The gores synchronously open out and unwrap during deployment with their edges pulled together by springs or other devices. No structural method is disclosed, however, to link the gores together once deployed. If flexible solid surface reflectors could be compressed into a smaller package and a means to hold their edges together once deployed were developed, these concepts should become commercially successful for space applications. This is the intent of the present invention.